The invention relates to an injection valve. Injection valves conventionally have a valve housing in which, for example, an actuator for controlling a servo valve is provided. The servo valve sets a pressure in a control chamber. Furthermore, the injection valve has a nozzle body which has a sealing seat and injection holes. A recess in which a nozzle needle is guided is made in the nozzle body. The nozzle needle is moved as a function of the pressure in the control chamber.
The recess has a pressure chamber which is connected to a fuel line of the housing. Since a fuel is guided at high pressure in the fuel line, particularly in the case of diesel injection valves, a sealing point is produced between the housing and the nozzle body. The sealing point is preferably sealed by the nozzle body being pressed against the housing. A clamping nut is provided for this purpose, said nut being connected to a thread of the housing and prestressing the nozzle body against the housing. The prestressing of the nozzle body requires large prestressing forces particularly at a high fuel pressure. The prestressing force has to be transmitted by the clamping nut to the nozzle body via an optimized geometry. For this purpose, it is known to form a bearing surface on the nozzle body, which surface is of conical design and tapers in the direction of the tip of the nozzle body.
At the same time, the clamping nut has a conical bearing surface which tapers in the direction of the tip of the nozzle body. A defined differential angle is made between the bearing surface of the nozzle body and the bearing surface of the clamping nut in order to ensure a defined surface pressure. At a very large prestressing force it has been shown that the action of force perpendicular with respect to the longitudinal direction of the nozzle body is relatively large and therefore produces an expansion of the clamping nut in the radial direction. Damage to the clamping nut may occur as a consequence.